1. Field of the Invention
The present invention relates to a drill adapter for a power screwdriver and having a locking device for releasably securing the drill adapter on the support region of the screwdriver and including a push-on sleeve supportable on the support region of the screwdriver and attachment means having a locking position in which the drill adapter is secured on the support region, and a release position in which the drill adapter can be mounted on or dismounted from the support region, with the attachment means having at least one engagement member supported in the push-on sleeve, a drill chuck for receiving a drilling tool and rotatable relative to the locking device and torque transmitting means for drivingly connecting the drill chuck with the tool spindle of the screwdriver.
2. Description of the Prior Art
Drill adapters of the type described above are used for expanding the function field of a pure screwdriver so that the screwdriver can also be used for drilling bores. E.g., it is possible to form guide bores in a workpiece, e.g., in a wood piece or a metal sheet, with a screwdriver equipped with a drill adapter of the type described above. After a bore is formed, the drill adapter is removed from the screwdriver, and the screwdriver can be used for screwing a screw in the formed bore.
U.S. Pat. No. 5,564,717 discloses a screwdriver adapter the push-on sleeve of which is so formed that it can be mounted over a depth stop which remains on the screwdriver. The locking device of the drill adapter includes an outer sleeve that displaceably retains the push-on sleeve and in which an adjusting or setting screw is arranged. For securing the drill adapter on the screwdriver, the setting screw is screwed relative to the depth stop as soon as a screw driving bit, which also remains in the screwdriver, engages in a screw head connected with the drill chuck.
The advantage of the known drill adapter consists in that both the screw driving bit and the depth stop remain in the screwdriver when the drill adapter is mounted on the screwdriver. This insures rapid mounting and dismounting of the drill adapter and a rapid change between the screwing and drilling functions of the screwdriver.
The drawback of the known drill adapter consists in that it is provided specifically for a screwdriver and is suitable only therefore. With this drill adapter, the screw driving bit, which remains in the screwdriver slightly projects beyond the depth stop or a front nose ring. Therefore, the application field of the known drill adapter is rather limited.
Furthermore, the connection between the drill adapter and the screwdriver is not sufficiently stable, which often results in malfunction during operation. Further, with the known torque transmission means, there exists a danger that upon mounting of the drill adapter on the screwdriver, the screw driving bit does not engage in the screw head correctly. This can result in damage. Moreover, when the drill adapter is mounted on the screwdriver, the outer sleeve must be brought with one hand in a certain position, in which the screw driving bit engages the screw head, and be held in this position. In this position of the outer sleeve, the adjusting or setting screw should be simultaneously tightened with another hand. Thus, none of the hand is free for holding the screwdriver. As a result, the mounting of the screwdriver is rather inconvenient.
An object of the invention is a drill adapter with which the foregoing drawbacks of the known drill adapter are eliminated.
Another object of the present invention is a drill adapter having a wide field of application and which can be handled much more easily than the known drill adapter.